User`s manual

DIGITAL-LOGIC AG MSLB-P5 Manual V0.3
PRELIMINARY 176
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Offset Type Description
3h Byte Controller index of CD drive
4h-7h Dword Logical Block Address
8h-9h Word Device specification:
For SCSI:
Byte 8: LUN and PUN of CD drive
Byte 9: Bus number
For IDE:
Byte 8 LSB: 0 = Master, 1 = Slave
Ah-Bh Word User buffer segment
Ch-Dh Word Load segment (only for Int 13h 4Ch):
00h = 7C0h
Eh-Fh Word Virtual sector count (only for Int 13h 4Ch)
10h Byte Low-order bits (0-7) of the cylinder count
(Matches returned CH of Int 13h 08h)
11h Byte Bits 0-5: Sector count
Bits 6-7: High order 2 bits of cylinder count
(Matches returned CL of Int 13h 08h)
12h Byte Head count (Matches returned DH of Int 13h 0h)
Bootable CD-ROM Service 4Dh uses a pointer to the Command Packet, described here:
Bootable CD-ROM Command Packet
Offset Type Description
0h Byte Packet size in bytes, currently 08h
1h Byte Count of sectors in boot catalog to transfer
2-h Dword Pointer to destination buffer for boot catalog
6-7h Word Beginning sector to transfer, relative to start of
the boot catalog. Int 14 4Dh should set this
value to 00h.
The following describes the Interrupt 13 Bootable CD-ROM Services of PhoenixBIOS 4.0:
Int 13 Bootable CD-ROM Services
AH = 4Ah Initiate disk emulation
Entry:
AL 00
DS:SI Pointer to Specification Packet (See above)
CF 0 = Specified drive emulating
1 = System not in emulation mode
AH = 4Bh Terminate disk emulation
Entry:
AL 00h = Return status and terminate emulation
01h = Return status only, do not terminate
DL Drive number to terminate
7Fh = Terminate all
DS:SI Empty Specification Packet
Exit:
DS:SI Completed Specification Packet (See above)
AX Exit status codes
CF 0 = System released
1 = System not in emulation mode
AH = 4Ch Initiate disk emulation and boot
Entry:
AL 00h
DS:SI Specification Packet (See above)
AH = 4Dh Return boot catalog
Entry :
AL 00h
DS:SI Point to Command Packet (See above)